//=================================================================================================
/*!
//  \file blaze/math/simd/Reduce.h
//  \brief Header file for the generic SIMD reduction functionality
//
//  Copyright (C) 2012-2020 Klaus Iglberger - All Rights Reserved
//
//  This file is part of the Blaze library. You can redistribute it and/or modify it under
//  the terms of the New (Revised) BSD License. Redistribution and use in source and binary
//  forms, with or without modification, are permitted provided that the following conditions
//  are met:
//
//  1. Redistributions of source code must retain the above copyright notice, this list of
//     conditions and the following disclaimer.
//  2. Redistributions in binary form must reproduce the above copyright notice, this list
//     of conditions and the following disclaimer in the documentation and/or other materials
//     provided with the distribution.
//  3. Neither the names of the Blaze development group nor the names of its contributors
//     may be used to endorse or promote products derived from this software without specific
//     prior written permission.
//
//  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
//  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
//  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
//  SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
//  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
//  TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
//  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
//  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
//  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
//  DAMAGE.
*/
//=================================================================================================

#ifndef _BLAZE_MATH_SIMD_REDUCE_H_
#define _BLAZE_MATH_SIMD_REDUCE_H_


//*************************************************************************************************
// Includes
//*************************************************************************************************

#include <blaze/math/functors/Forward.h>
#include <blaze/math/simd/Prod.h>
#include <blaze/math/simd/SIMDPack.h>
#include <blaze/math/simd/Sum.h>
#include <blaze/math/simd/Storea.h>
#include <blaze/util/typetraits/AlignmentOf.h>


namespace blaze {

//=================================================================================================
//
//  SIMD REDUCTION
//
//=================================================================================================

//*************************************************************************************************
/*!\brief Reduces the elements in the given SIMD vector.
// \ingroup simd
//
// \param a The SIMD vector to be reduced.
// \param op The reduction operation.
// \return The result of the reduction operation.
*/
template< typename T, typename OP >
inline decltype(auto) reduce( const SIMDPack<T>& a, OP op )
{
   using ValueType = typename T::ValueType;

   alignas( AlignmentOf_v<ValueType> ) ValueType array[T::size];
   storea( array, ~a );

   ValueType redux( array[0UL] );
   for( size_t k=1UL; k<T::size; ++k ) {
      redux = op( redux, array[k] );
   }

   return redux;
}
//*************************************************************************************************


//*************************************************************************************************
/*! \cond BLAZE_INTERNAL */
/*!\brief Reduces the elements in the given SIMD vector by means of addition.
// \ingroup simd
//
// \param a The vector to be summed up.
// \return The sum of all vector elements.
*/
template< typename T >
inline decltype(auto) reduce( const SIMDPack<T>& a, const Add& /*op*/ )
{
   return sum( ~a );
}
/*! \endcond */
//*************************************************************************************************


//*************************************************************************************************
/*! \cond BLAZE_INTERNAL */
/*!\brief Reduces the elements in the given SIMD vector by means of multiplication.
// \ingroup simd
//
// \param a The vector to be reduced by multiplication.
// \return The produdct of all vector elements.
*/
template< typename T >
inline decltype(auto) reduce( const SIMDPack<T>& a, const Mult& /*op*/ )
{
   return prod( ~a );
}
/*! \endcond */
//*************************************************************************************************

} // namespace blaze

#endif
